method allowing visualization of conductive solid surfaces with atomic resolution; conductive tip is scanned across the surface of the wafer; information about the physical features of the surface is based on the measurement of the tunneling current between the tip and the surface atoms.

AFM

Atomic Force Microscopy; method capable of surface visualization with near-atomic resolution; measurement of roughness of solid surfaces based on electrostatic interactions between surface and measuring tip; tip can be set above the surface, on the surface, or can tap the surface oscillating at high frequency (tapping mode).

tunneling, tunneling current

transport of electron across the potential barrier without changing its energy; as opposed to electron transport "over" the barrier (thermionic emission) in which case its energy is must be changed; tunneling probability is a strong function of the width ofpotential barrier; examples: tunneling across the potential barrier at the metal-semiconductor contact, or across the potential barrier at the p-n junction, or across an oxide (direct tunneling for oxide thinner than about 3 nm, Fowler-Nordheim tunneling for oxide 5-10 nm thick) in MOS structure.